Recently, the ISEAL Alliance launched a new website under the challenging title of ‘Evidensia’ that provides a comprehensive overview of available studies on the effects of commodity certification for different outcome areas (like farmers income, environmental effects and social benefits). This effort for bringing together a whole range of studies, reports, articles and books that assess the effects of certification is highly laudable, and at the same times also invites to reflections on next steps and challenges for useful future studies on commodity certification. I would like to share four challenges.

First, the overview of studies presented on the Evidensia website makes careful difference between various types of evidence, but does not fully consider the opportunities for linking the evidence derived from different sources. Carefully designed impact studies that are based on a robust fieldwork design and representative samples might give insights on significant welfare and sustainability impact, that may be complemented with in-depth interviews and comparative case studies that inform on the subjective satisfaction with certification programs. based on anecdotal evidence from a small number of interviews. The systematic reviews on the effects of certification excluded a substantial number of the published studies precisely because they could not be considered as credible evidence. ISEAL could support best practices by commissioning mixed methods field studies based on a set of minimum criteria that should be fulfilled.

Second, it would be wise to include studies that address certification at different scales. Most evidence seems to be available at farm-household and community level. Almost no studies are included that carefully assess impact on income distribution and bargaining power within households. In a similar vein, sound evidence on changes in value chain relationships and shifts in added value distribution between farmers, traders, processors and retailers due to certification seems to be barely available. We argued at the recent ISEAL meeting that much can be learned from efficiency gains upstream or downstream in the value chain, instead of keeping the focus on measuring field-level efficiency. It might therefore be useful to expand the Evidensia reach to studies and articles in the fields of business management studies and supply chain organization.

Third, it is deemed necessary to link the reported outcomes from Evidensia with the theory of change that is underpinning certification initiatives.  It is sometimes argued that only adoption of improved practices and changes in farm management as proximate outcomes can be assessed, while others insist in the measurement of final income and net revenue effects. The latter studies usually suffer from lack of information on other household and off-farm activities. Even more complicated (and also disappointing) are the results from the scarce studies that looked at food security and nutrition outcomes. One could make a convincing argument that major behavioural change effects should be registered (e.g.in the fields of risk attitudes, trust between value chain partners, loyalty to the cooperative) and that these can in turn be expected to have an impact on other farm-household decisions and outcomes. This would imply that more attention is given to experimental and behavioural impact studies of the effects of commodity certification.

Fourth, the learning from impact and evidence studies seems to be hindered by the overwhelming – and sometimes highly contradictory – outcomes from different studies. In part, these differences are the result of the research approach that has been used, but otherwise there are also real differences in perceptions that deserve to be further discussed and analysed. It would therefore be wise to identify some key areas where evidence is mixed or contradictory, and try to dig deeper into the perceived impact pathways that are considered. This may pave the way for further discussion on how certification initiatives can be deepened in order to enhance their impact.